Love that evening sky.
Can I offer advise on the fly picture? Sure?
You camera was taking a general reading of the light, and that meant it exposed for the pale background meaning that the fly is underexposed and too dark to show detail. I'm not sure if our cameras have selective metering somewhere in the depths of the menu, but until I have figured that one out, I think in this situation I would add 2/3 stop - I think the background would handle it OK.
Right, now can you find another fly?